Saving the Intuitions:

Polylithic Reference

Ioannis Votsis, 10/04/08

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Plan

(1) Introduction

(2) Descriptive, Causal and Hybrid Theories

(3) Conflicting Intuitions

(4) Polylithic Reference

(5) Reference and Truth

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Preamble• A realist view of science seems to require that:

- Explanatory and empirical success (of a given grade) is a good indicator of the approximate truth of a theory or of certain theory-parts.

- Approximately true theories/theory-parts describe the unobservable world, its entities and processes.

- Successor theories (with success of a given grade) are closer to the truth than their predecessors and preserve (at least in some limit form) their predecessors’ approximately true parts (if they have any) and hence any related ontology.

- Referential stability or continuity through theory change ensues after the rise of a theory with approximately true parts.

- A theory of scientific term reference provides not only the mechanics of reference but explicates this referential stability.

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Theories of Reference

• Three central questions:

(A) How is reference fixed?(B) How does reference and truth relate?(C) How does reference and meaning relate?

• I will also mainly focus on scientific term reference (e.g. observational, theoretical and natural kind terms). What I will say here need not apply to an analysis of everyday language term reference.

• I will focus on questions A and B. Although question C is related and important, I will largely ignore it for the purposes of this paper.

• Aim:

I will explore a largely ignored corner of the space of possible relations between scientific realism and theories of reference.

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Descriptive TheoriesMain idea: Reference is fixed by virtue of a term’s associated

descriptions.

Some intuitions satisfied:

- I can successfully talk about a thing only when all my ideas about it hold. Otherwise, I’m not really talking about that thing.

Notable Proponents: Frege, Russell and Searle.

- if you and I don't share a consistent set of ideas about some thing we could not be talking about exactly the same thing!!!

Sample: A term t occurring in scientific theory T refers to an entity a if and only if a satisfies the descriptive claims T associates with t.

- to attempt to really talk about some thing we at least need to attempt to somehow describe it.

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Problems

(b) Unnecessary: We seem perfectly capable of referring to things about which we have little to no knowledge.

Reply: Some descriptive knowledge is required, otherwise reference becomes too easy.

(c) Ntity-lity: How many and/or which descriptions are enough? Otherwise put, how do we define the special subset?

Replies: majority, mature science, central concepts, essential properties, etc.

(a) Too strict: None of our theories are exactly right, so no scientific term refers. Moreover, two theories that assign conflicting claims to a term t cannot be referring to the same object.

Reply: Modified descriptivism, e.g. a term t refers to an object a iff a satisfies a certain special subset of the descriptions associated with t.

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Causal TheoriesMain idea: Reference is fixed by virtue of a term’s causal history.

Some intuitions satisfied:

- I can successfully talk about a thing even when all my ideas about it are incorrect.

Sample: A theoretical term t refers to an entity a if and only if either t is used to originally dub a (typically via ostension) xor t was used to originally dub a and any speaker’s subsequent use of t is causally linked back to the original dubbing.

Notable Proponents: Kripke, Putnam and Devitt.

- you and I may talk about the same thing even if we have conflicting ideas about it.

Qualification: The dubbing event may include descriptions and may even be based solely on descriptions (e.g. Neptune).

- to talk about some thing typically involves causal contact with the world.

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Problems

(b) Too liberal: Any old term ends up referring to modern-day entities.

Reply: Further conditions apply, i.e. the principle of the Benefit of Doubt.

(c) Ntity-lity: How many and/or which descriptions are enough? Otherwise put, when are we justifiably charitable?

Replies: majority, mature science, central concepts, essential properties, etc.

(a) Inescapability: In scientific contexts, at the very least the following description is always assumed to be satisfied “The entity that caused our current use of the term ‘_____’ ”.

Reply: Not the same idea of descriptive content envisioned by descriptivists.

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Causal-Descriptivist TheoriesMain idea: Reference is fixed by a combined causal-descriptive strategy.

Notable Proponents: Evans, Lewis, Kroon and Psillos.

• Psillos’ view: “A term t refers to an entity x if and only if x satisfies the core causal description associated with t” (1999, p. 296).

Q: What is the core causal description?

A: It is the description of “the [kind-constitutive] properties by virtue of which it [i.e. a posited entity] plays its causal role vis-à-vis the [relevant] set of phenomena” (p. 295).

Q: What are kind-constitutive properties?

A: They “are those whose presence in an item makes that item belong to a kind” (p. 288).

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Psillos’ View (1)Referential Continuity: “Two terms t’ and t denote the same entity if and only if (a) their putative referents play the same causal role with respect to a network of phenomena; and (b) the core causal description of t’ takes up the kind-constitutive properties of the core causal description association with t” (p. 296).

Some intuitions satisfied:

- some sort of causal contact with the world is maintained.

- I can successfully talk about a thing only when my central ideas about it hold.

- we can talk about the same thing over time so long as our past central ideas about it still hold.

Example: ‘Ether’ refers to the electromagnetic field.

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Psillos’ View (2)• Problem 1: Psillos’ two definitions of reference don’t always match.

Psillos’ reply: “These issues are serious enough. However, they are not intractable… For instance, some descriptions associated with a term are less fundamental in view of the fact that the posited entity would play its intended causal role even if they were not true” (ibid.).

• Problem 2: Psillos correctly notes: “But, an objector may ask, how (and when) is the core description to be singled out?” (p. 297). The ntity-lity problem strikes again!!!

Example: Suppose that James Ladyman has, among other things, two kind-constitutive properties, ‘creature with a heart of gold’ and ‘creature with a fist of steel’. The core causal description of term t’ contains only ‘creature with heart of gold' and the core causal description of term t contains only ‘creature with a fist of steel‘.

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Psillos’ View (3)

• Desideratum: An adequate account of reference should be able to provide a non-ad hoc and unambiguous answers to questions of referential failure or success (including referential continuity) .

Note: I am not arguing here that Psillos’ theory is a lost cause. I’m simply pointing out some of its difficulties.

Example: We might contest Psillos’ account of the ether’s core causal description, arguing that the following fundamental properties were not taken up by the mature electromagnetic field’s core causal description, e.g. that the ether is a material and mechanical medium capable of containing energy as it is transmitted from one body to another, that ether molecules oscillate, that transverse waves require a solid medium, etc. (Stanford 2003, Holton and Brush 2001).

• Problem 3: Though a reasonable answer, it still doesn’t give us a non-ad hoc and unambiguous way to determine the fundamental from the non-fundamental descriptions.

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Saving the Intuitions• Some of the aforementioned intuitions are conflicting, e.g. whether we

can successfully talk about a thing when all of our non-trivial ideas about it are false, whether a single contradictory idea entails that we cannot be talking about the same thing, whether causal contact is necessary, sufficient, both or neither, etc.

OR save all the intuitions and find some way to reconcile them.

Dilemma:

EITHER reject the conflicting intuitions as somehow faulty and on that basis choose a theory of reference that satisfies the remaining intuitions – this is the option we were just looking at.

NB: That reference is not monolithic can still be explored under the auspices of the former option.

• I will explore the latter option by supposing that the concept of reference is not monolithic.

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Polylithic Reference

Qualifications:

(1) I will not here argue that this is the only or even the best way to understand the notion of reference.

• Motivation: Naturally to save our varied and contrary intuitions.

Note: Kitcher’s (1993) token-type account of reference comes closest to conveying the same idea.

(2) I will not here present an exhaustive list of notions of reference or even tell you how many are required.

(3) I will present an outline of three candidate notions each satisfying different standards and different sets of intuitions. The three notions may require modification, replacement or even deletion.

(4) Intricacies involving a speaker’s intentions have been avoided, though they may be integrated to further enrich the resulting formulations.

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ReferenceICS (1)

Qualification: A term that refers(ics) might also refer in some other way. Also, even though it is a very easy notion of reference to satisfy, it is not trivially satisfied.

• Ref(ics): A term t employed during period x refers(ics) to an entity a iff t was used during period x to identify the causal source of a certain set of phenomena associated with a, EITHER via some description OR via actual contact with the source.

Motivation: Saves our intuitions about not neglecting causal contact and about our ability to talking about things despite false (or wildly diverging) associated ideas.

Note: This kind of reference establishes a very thin referential continuity that’s not sufficient to tackle historical objections.

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ReferenceICS (2)

Note: Friedman (2001) offers an even more radical account of the continuity between Aristotelian and classical physics.

• Referential success example: Aristotle’s ‘tends towards its natural place’ refers(ics) to gravity as spacetime curvature.

- Aristotle’s notion was postulated to explain among other things phenomena relating to falling objects. Since such phenomena are associated with our modern understanding of gravity, the term ‘tending towards its natural place’ refers(ics) to gravity as spacetime curvature.

“… in the sublunary region close to the surface of the earth, where the earth is by far the principal gravitating body, heavy bodies do follow straight paths directed towards the centre of the earth, again to an extremely good approximation” (p.379).

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ReferenceICS (3)

• Referential failure example: The term ‘celestial sphere’ does not refer(ics) to gluons.

- The celestial spheres were postulated to explain celestial phenomena like the daily motion of the fixed stars but not the kind of phenomena we associate with gluons, namely that it mediates strong interactions between quarks, binds protons and neutrons in atomic nuclei, etc.

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ReferenceMND (1)• Ref(mnd): A term t employed during period x refers(mnd) to an entity a

iff t was used during period x to identify the causal source of a certain set of phenomena associated with a AND a satisfies some of the non-trivial theoretical claims the relevant scientific theory associates with t.

Motivation: Saves our intuitions about the importance of identifying a causal source and about successfully talking about a thing when at least one of our ideas about it holds.

• RefCont(mnd): Term t’ employed during period x and term t employed during period y are referentially continuous(mnd) with respect to an entity a iff t' and t refer(mnd) to a AND t' inherits (some/all)* of the satisfied descriptive claims of t".

Note: This last definition does not aim to re-describe the conditions of reference and hence avoids the mismatch error.

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ReferenceMND (2)

Example of referential continuityMND failure: The term ‘humour’ is not referentially continuousMND with the term ‘leukocytes‘.

Example of referentialMND and referential continuityMND success: Early 19th century's 'caloric' refersMND and is referentially continuousMND to modern thermodynamical accounts of heat because all the correct descriptive content associated with the caloric is preserved in the modern account.

• Note1: This notion is a bit harder to satisfy. It establishes a thicker kind of referential continuity capable of tackling some historical objections, e.g. part of the old theory about the object must be: (i) correct and (ii) preserved in the new theory.

• Note2: No ntity-lity problem!!! One description is enough to establish ref(mnd) and referential continuity(mnd) between two theories.

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ReferenceMXD

• Ref(mxd): A term t employed during period x refers(mxd) to an entity a iff t was used during period x to identify the causal source of a certain set of phenomena associated with a AND a satisfies all (and only) the descriptive claims the scientific theory associates with t.

Motivation: Saves our intuitions about the importance of identifying a causal source and of reference that gets all and only the scientific theory’s descriptions right.

Note: This notion is very hard to satisfy. A referential continuity notion based on reference(mxd) would not be of help to problems of conceptual change.

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Ad hoc / Post hoc Problems• A problem facing any theory of reference that incorporates clauses

about correct descriptions is the following:

No prospectively applicable criteria: One can only identify the correct descriptions by virtue of the fact that these have been preserved in subsequent accounts of the object. Hence the condition that new theories preserve the correct descriptions of the old ones is trivially satisfied. (Stanford, 2006, pp.168-183).

• Replies:

(1) We can run partly-independent checks on the descriptions.

(2) We can also run a historical check: A set of descriptions preserved in the transition between theories T1 and T2 typically must also be preserved in the transition between T2 and T3.

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Does Realism require Reference? • Laudan: “[A] necessary condition… for a theory being close to the

truth is that its central explanatory terms must genuinely refer” (1981, p.33).

• Hardin and Rosenberg (1982) deny the view that reference is a necessary condition for approximate truth.

Example: “… there is nothing like a gene in the sense envisioned by Mendel” (p. 607).

Problem: To the extent that the Ramsey sentence of a theory or an unramsified theory are approx. true, they are surely telling us something about unobservable entities and hence some sort of reference to these entities is unavoidable.

• Cruse and Papineau (2002): The cognitive content of a scientific theory is captured by its Ramsey sentence and the latter makes reference irrelevant.

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In Memoriam

Delft, June 2007